无法从C ++ Win32程序连接到命名管道

Question

I have two programs that run on the same computer and I need them to talk. One is an existing program written in C++ using the older windows32 framework. The other is a newly written C# application using the .NET framework. My newer .NET application will act as the server and the older existing application the client.

I have the named pipe created on both the client and server. I am just not able to get them to connect. I suspect the problem is simply I am not matching the file name correctly (named pipes use files in the background).

Here is the .NET server code:

    private volatile NamedPipeServerStream pipeServer;
    pipeServer = new NamedPipeServerStream("MyPipe", PipeDirection.InOut);
    pipeServer.WaitForConnection();

Here is the older existing win32 client code:

HANDLE pipe = CreateFile(
    "\\Device\\NamedPipe\\MyPipe",
    GENERIC_READ | GENERIC_WRITE, // only need read access
    FILE_SHARE_READ | FILE_SHARE_WRITE,
    NULL,
    OPEN_EXISTING,
    FILE_ATTRIBUTE_NORMAL,
    NULL
);

I run the server code first and it sits there waiting for a connection. Every single time my handle is equal to INVALID_HANDLE_VALUE .

I used ProcessExplorer to see if I can find the true name of the pipe. According to ProcessExplorer the name is \\Device\\NamedPipe\\MyPipe .

I think I am matching this on my client side. If anyone can lend a suggestion I am appreciative. Thanks.

Answer 1

To open a named pipe with CreateFile , you need to specify the file name as \\\\.\\pipe\\name , so in your case it would look like:

HANDLE pipe = CreateFile(
    "\\\\.\\Pipe\\MyPipe",
    GENERIC_READ | GENERIC_WRITE, // only need read access
    FILE_SHARE_READ | FILE_SHARE_WRITE,
    NULL,
    OPEN_EXISTING,
    FILE_ATTRIBUTE_NORMAL,
    NULL
);

Answer 2

Setting PipeSecurity solved this issue for me. Making it accessible for Everyone looks less secure but it worked.

PipeSecurity ps = new PipeSecurity();
PipeAccessRule psRule = new PipeAccessRule(@"Everyone", PipeAccessRights.ReadWrite, System.Security.AccessControl.AccessControlType.Allow);
ps.AddAccessRule(psRule);
 NamedPipeServerStream pipeServer = new NamedPipeServerStream("datapipe", PipeDirection.InOut, 1, PipeTransmissionMode.Message, PipeOptions.Asynchronous, 1, 1, ps);

Source: Named Pipe Error - System.UnauthorizedAccessException: Access to the path is denied.